It is a whole new science with important implications for the treatment of disease - most notably cancer.

Epigenetics is the study of molecular modifications which sit on top of the DNA in our cells, in effect switching our genes on and off; telling our cells how they should behave.

Scientists are now realising that if those epigenetic markings are disrupted, causing a gene to become incorrectly active or silent, a healthy cell could become diseased.

»news.bbc.co.uk/2/hi/health/7155854.stm